Vented double skirt system

ABSTRACT

An improved sealing arrangement for isolating the enclosure which is exposed to a source of reduced pressure to establish air flow, and which houses a floor treating means such as an axially rotatable brush from ambience. The improved seal means includes a plurality of generally parallelly disposed spaced apart sealing elements cooperatively arranged to define a seal chamber therebetween, and a vent opening is formed in one of the sealing elements to provide gaseous fluid communication between the seal chamber and the enclosure housing the floor treating means.

United States Patent 1 1 Christensen et a1.

[ VENTED DOUBLE SKIRT SYSTEM [75] Inventors: Bryan L. Christensen; David W.

Berg, both of Minneapolis, Minn.

[73] Assignee: Tennant Company, Minneapolis,

Minn.

22 Filed: Mar. 16, 1973 211 Appl. No.: 341,975

[52] US. Cl. 15/368; 15/340; 15/347 [5 I] Int. Cl A471 9/06 [58] Field of Search 15/347, 340, 368

[56] References Cited UNITED STATES PATENTS 514,678 2/1894 Furnas 15/340 X 1,005,290 10/1911 Overholt 15/347 X 1,222,454 4/1917 Overholt 15/347 X 3,233.274 2/1966 Kroll 15/340 1111 3,892,008 1451 July 1,1975

3,512,206 5/1970 Young 15/340 X 3,736,619 6/1973 Zamboni 15/340 3,755,851 /1973 Williams 15/340 X Primary Examiner-Harvey C. Hornsby Assistant ExaminerC. K. Moore [57] ABSTRACT An improved sealing arrangement for isolating the enclosure which is exposed to a source of reduced pressure to establish air flow, and which houses a floor treating means such as an axially rotatable brush from ambience. The improved seal means includes a plurality of generally parallelly disposed spaced apart sealing elements cooperatively arranged to define a seal chamber therebetween, and a vent opening is formed in one of the sealing elements to provide gaseous fluid communication between the seal chamber and the enclosure housing the floor treating means.

11 Claims, 8 Drawing Figures PATWTEHJUU 1915 @892 008 SHEET 1 kw mm 1 VENTED DOUBLE SKIRT SYSTEM CROSS-REFERENCE TO RELATED APPLICATION The present skirt seal system may be employed in the apparatus disclosed in the co-pending application of Ralph C. Peabody, Ser. No. 341,975, filed Mar. 16, 1973 and entitled POWER FLOOR TREATING AP- PARATUS.

BACKGROUND OF THE INVENTION The present invention relates generally to an improved floor sweeping apparatus, and more specifically to an improved sealing arrangement for isolating the floor treating means of a floor sweeper from ambience, the floor treating means being exposed to a source of reduced pressure, commonly referred to as vacuum", to establish air flow. The seal provides improved dust control for floor sweeping apparatus, with a significant reduction in dust generation being experienced with the improved seal means of the present invention.

Power driven floor sweeping devices are in wide use, and particularly in commercial establishments such as factories, office buildings, parking ramps, and the like. These sweeping devices are employed for removal of dust, dirt, as well as other debris from floor surfaces. Typically, these devices provide for the controlled flow of gaseous fluid from an area or enclosure exposed to the surface being treated into a dust or other solid particle removal or separation chamber which is at a reduced pressure. The separation chamber is held at a reduced pressure, with a dust removing filter being interposed within the chamber and rigidly held therewithin. For removal of larger or heavier particles of debris, a rotating brush is employed to make brushing contact with the floor surface and move the debris from the surface into a hopper. The airsuspension of dust or solid particles generated from this operation is carried through an evacuation port for ultimate transfer to a filter mounted in the separation chamber.

While brush rotation is necessary for raising debris from a floor surface, this motion frequently contributes to the raising of quantities of dust in the ambunce. In order to reduce the quantity of dust being raised, a reduced pressure is provided in the brush chamber and seals are employed between the structure and the floor surface for isolating the brush chamber or enclosure from ambience. Again, typically, these seals are in the form of a resilient skirt or the like which extends generally between the lower edges of opposed walls of the brush enclosure and normally reach approximately to the surface of the floor being treated.

SUMMARY OF THE INVENTION In accordance with the present invention, an irnproved sealing skirt is provided which has been found extremely effective in the reduction in the quantity of dust-laden air generated by the brush and discharged into the area being treated. Briefly, the improved skirt means of the present invention includes a plurality of generally parallelly disposed and spaced apart sealing elements which form a seal chamber or sealing chamber therebetween. Normally, a pair of such sealing elements are employed in the brush housing, and the elements extend between opposed walls such as, for example, between opposed side walls. In such an arrangement, the skirt means are tandemly arranged and, in effect, form a seal pair. A vent opening is formed in one of the sealing elements to provide gaseous fluid communication between the brush enclosure and the chamber formed by the sealing elements. This venting is be lieved to contribute to the reduction in pressure drop which will normally exist between the brush surface and ambience, and thus provide a zone free of turbulence which enables dust particles which may otherwise be discharged into ambience to be either permitted to settle, or re'introduced into the brush enclosure. and ultimately discharged into the solid-air separation or debris receiving chamber.

Therefore, it is a primary object of the present invention to provide an improved skirt seal means for a floor sweeping apparatus which contributes significantly to a reduction in the discharge of dust into ambience.

It is a further object of the present invention to provide an improved floor sweeping apparatus which employs a sealing arrangement having a plurality of generally parallelly disposed and spaced apart sealing elements which form and define a seal chamber or sealing chamber therebetween, with at least one vent opening being formed in one of the sealing elements to provide gaseous fluid communication between the brush enclosure and the seal chamber.

It is yet a further object of the present invention to provide an improved floor sweeping apparatus utilizing an axially rotating brush, with skirt means being provided in the brush enclosure for forming first and second parallelly disposed spaced apart sealing elements cooperatively arranged to form a seal pair, and providing means for improving the abilityof the apparatus to maintain dirt and other debris in suspension for ultimate discharge into the debris receiving chamber.

Other and further objects of the present invention will become apparent to those skilled in the art upon a study of the following specification, appended claims, and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a side elevational view of the improved floor sweeping apparatus of the present invention, with portions of the housing being cut away so as to illustrate details of the brush enclosure and debris receiving chamber;

FIG. 2 is a detail perspective view, partially broken away, and illustrating the improved seal means of the present invention as disposed within the apparatus;

FIG. 3 is a vertical sectional view of the floor sweeping apparatus as illustrated in FIG. I, and showing the debris receiving chamber in open dosposition in solid lines, and in closed disposition in phantom, with this view being taken generally along the line and in the direction of the arrows 3-3 of FIG. 7;

FIG. 4 is a detail vertical sectional view of the brush receiving enclosure, with the central portion of the brush being shown in phantom to better illustrate other features of the apparatus;

FIG. 5 is a fragmentary side elevational view, par tially broken away, illustrating details of the brush suspension and drive system;

FIG. 6 is a fragmentary side elevational view, partially in section, and illustrating the drive means for delivering power to the drive wheel;

FIG. 7 is a perspective view of the improved floor sweeping apparatus of the present invention; and

FIG. 8 is a fragmentary vertical sectional view taken along the line and in the direction of the arrows 8-8 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT In accordance with the preferred embodiment of the present invention, the floor sweeping apparatus generally designated 10 includes a frame means 11 in the form of a structural housing including a top panel 12, a front panel 13, a rear panel 14, and a pair of laterally opposed side panels 15 and 16. The housing further is arranged to receive a removable debris hopper or receiver 17, as is illustrated in FIG. 3. The hopper is appropriately sealed into contact with the remaining portions of the structure, as is apparent from the showing in FIG. 3. A control handle 18 is provided, with handle l8 having a pair of laterally disposed arms 18A and 18B secured to top panel 12 of the frame means 11, and with a gripping section being provided as at 18C. The support wheels include a pair of forwardly disposed casters 19 and 20, and a rearwardly disposed drive wheel 21. The forwardly disposed casters are adapted for rotation, as is conventional, by means of mounting plate or post as at 22, the casters being secured to a main support plate 23, as indicated in FIG. 1. Rear drive wheel 21 is mounted for rotation on axle shaft 25, with power being delivered to drive wheel 21 by means of a drive assembly to be described in further detail hereinafter.

As is apparent from the drawings, the apparatus includes a floor treating means in the form of a cylindrical brush 27 which is journaled for axial rotation within the frame means. The details of the mounting of the cylindrical brush 27 are best illustrated in FIG. 4, it being noted that the cylindrical brush 27 includes a core 28 which is arranged to receive the hubs 29 and 30 there within. As is apparent in the illustrations of FIGS. 5 and 6, hubs 29 and 30 are arranged along a common axis and provide a convenient means for supporting cylindrical brush 27. The core 28 of brush 27 is positively engaged with hub 29 to provide for a proper drive coupling. A key or a radially extending rib may be employed if desired with a matching receiving slot being formed in the brush core. For reduction of friction u on mounting the brush in the system, the core engaging portion of boss 30 is preferably hexagonal. In order to provide for freedom of rotation of hubs 29 and 30, suitable journal bearings are provided in the mounts as at 31. Also, as is apparent in FIGS. 5 and 6, hubs 29 and 30 are supported on laterally disposed mounting bracket 32 and arm 33. Support for bracket 32 and arm 33 is obtained from plate 34 which is hingedly secured to frame plate extension 35 as at 36 and 37, plate 34 thus being a transverse support member for bracket 32 and arm 33. Hinge elements 36 and 37 utilize a flexible coupling web such as a web of polypropylene as is illustrated at 38, this web providing hinged support or coupling between plates 34 and 35 and thus permitting free-floating or brush 27 while in use. This suspension system has been found to reduce the amount of vibratory energy which is transferred from the rotating cylindrical brush 27 to the remaining portions of the frame,

As is apparent in the drawings, the brush enclosure includes a forward wall such as wall 13, a rear wall at 40, and opposed side walls 15 and 16. A receiving post for air suspended dust or debris is formed in wall 40 as at 41, and a conduit 42 extends from the brush receiving enclosure 43 to the air suspended dust or debris receiving enclosure generally designated 44. Chamber 44 acts as a solid-air separating chamber with filter 45 being employed to separate the incoming portion of the chamber as at 46 from the discharge portion of the chamber as at 47. Exhaust conduit 48 extends from chamber segment 47 to exhaust port 49 which comm unicates with ambience. Impeller S0 housed within casing 51 is utilized to generate fluid flow from the enclosure 43 to the chamber 44. Impeller is mounted on shaft 52, with rotational energy being delivered to the impeller by means of belt 53, belt 53 being driven from shaft 61 which is coupled to the drive shaft 60A of motor 60 along plural spans including belt span 6013, with the spans covering pulleys 60C, 60D and others. Suitable journal bearings are provided as illustrated in FIG. 8 of the drawings.

Attention is now directed to FIG. 5 of the drawings for a discussion of the suspension and support system for the rotating brush assembly. As is apparent in this view, arm 33 supports hub 30 which, in turn, is received within the core of cylindrical brush 27. The axial height of brush 27 when raised for transport or other reasons is adjustably controlled by means of threaded control shaft 55 which engages internally threaded coupling 56, and which is provided with a support step or collar as at 57 for engaging a key-hole opening in frame or housing top panel 12. Key-hole bore is formed in top panel 12 as at 58 for receiving the shank of member 55. The phantom view of lever 55 is provided to illustrate the free-floating lower or running disposition of cylindrical brush 27, as is illustrated in phantom at 59.

Motor 60 is provided in order to deliver power for imparting axial rotation to the cylindrical brush 27. The drive shaft 60A of motor 60 drives output or countershaft 61 (FIG. 5) through a belt with brush drive pulley 62 being fast on shaft 61. Belt 63 is utilized to deliver power to pulley 64 which is, in turn, fast on shaft 29A of hub 29. Idler pulley 66 is provided for maintaining desired tension in belt 63, with idler 66 being mounted on link 67 which is pivotally secured to the frame on shaft 68. Adjustable spring member 69 has one end coupled to link 67, with its other end being secured to the frame. A second spring is shown at 70 for maintaining or regulating the amount of down-pressure on brush 27. Spring 70 has its forward end secured to support plate 34, with its rearward end being adjustably coupled to the frame through eye-bolt 71. The position of eye-bolt 71 is determined by wing nut 72.

Attention is now directed to FIG. 6 of the drawings for an illustration of the drive means. Drive wheel 21 is driven from shaft 61 by means of pulley 74, pulley 74 being fast on shaft 61, with belt 75 engaging pulleys 74 and 76. Adjustable idler pulley 77 is mounted for rotation on a shaft secured to crank arm 78, arm 78 being secured to bracket 80. Bifurcated coupling 82 is pro vided at the end of cable 83 for controlling the disposition of idler 77 and the ultimate tension in belt 75. In the position illustrated in FIG. 6, the arrangement is in drive" disposition, and counter-clockwise motion of arm about pivot pin 81 will reduce tension in drive belt 75, thus permitting the unit to rest with the engine at idle.

Attention is now directed to the details of the seal means illustrated in FIGS. 2 and 3. Skirt means generally designated 85 are provided, and are coupled to the wall means at the rear of chamber 43. Skirt means 85, which isolate enclosure 43 from ambience, include first and second tandemly arranged spaced apart sealing el ements 86 and 87. These sealing elements 86 and 87 are cooperatively arranged to form a seal pair and define a seal chamber 88 therebetween.A pair of vents are provided as at 89 and 90 for providing gaseous fluid communication between the chamber 43 and the seal chamber 88. The combined area of vents 89 and 90 is preferably substantially equal to the area of port 41. As is apparent in the drawings, vents 89 and 90 are preferably spaced apart and disposed generally adjacent the opposed side walls l5 and 16 of chamber 43. Also, these vents are formed in the skirt which is adjacent that portion of the brush which, in its normal running disposition, forces debris thereagainst.

In addition to the seal means 86 and 87, a further seal is provided as at 93 for providing further isolation of the chamber 43 from ambience, seal means 93 also providing a gasket for debris receiving hopper 17. An upper forward seal is shown at 93A, this seal performing a similar gasketing function. Lateral seals are also provided.

As illustrated in this embodiment, the seals which are utilized to form the seal chamber extend between opposed side walls at the rear of the brush housing. As will be appreciated, such seal arrangements may extend between any opposed walls, and in certain instances, may be designed to extend around and circumscribe the entire brush housing to form an annular seal chamber thereabout. A suitable bent or plurality of vents would be established to provide communication between the seal chamber and brush housing.

While the embodiment illustrated herein employs a pair of spaced apart vents establishing communication between the seal chamber and the brush housing, it will be appreciated that adequate venting may be achieved by utilizing a single such vent opening, or by employing a larger number of such openings. It will be appreciated, therefore, that alternate venting arrangements may be established to achieve the performance and results of the present invention.

Particular attention is now directed to FIG. 4 of the drawings for a detailed discussion of the manner in which brush 27 may be removed from the assembly. As has been previously indicated, brush 27 is provided with a core 28 which is received on hubs 29 and 30 of the opposed bosses. Arm 33 is resilient and is inwardly biased so as to firmly engage and retain brush 27 in operating disposition. For removal of brush 27, the operator will press arm 33 outwardly so as to disengage the surface of hub or boss 30 from the core 28 of brush 27, thereby permitting the brush to be dropped.

While the structure has been illustrated as being provided with a gasoline engine 60, it will be appreciated that alternate forms of power may be provided such as by electrical motor means or the like.

In the air suspended dust-receiving chamber 44, hinge means are provided as at 97 for enabling the operator to open the chamber and remove accumulated debris therefrom. A lock is provided as at 98 to ensure closure of chamber wall 99 when the unit is in operation. As is apparent in the drawings, filter 45 is received within the confines of a gasketed perimeter as at 100, with the gasket employing a pair of generally parallelly disposed lips 101 and 102 for making contact with the outer periphery 103 of filter 45. It has been found that the positioning of filter 45 within the confines of arms 18A and 18B of handle 18 enhances the delivery of vibratory energy from the engine to the filter, and thus tends to render it self-cleaning while the unit is in operation.

Hopper 17 is also removable from the assembly, as is conventional in power sweeper devices of this type. Large items of debris which are collected in hopper 17 by rotation of brush 27 are thus conveniently transported to a suitable place of disposal.

For purposes of operating stability, while the three support wheels including castors l9 and 20 and drive wheel 21 are generally sufficient, additional support may be made available to the structure by means of ele vated castors or support wheels 105 and 106. These units may assist in preventing the unit from tipping sufficiently far from its normal running disposition so as to protect the integrity of seals 86 and 87.

The materials of construction to be utilized for the device are conventional. Seals 86 and 87 are preferably that of reinforced rubber or the like. Such seal material is, of course, commercially available and any of a variety of resilient flexible materials may be employed for this purpose.

We claim:

1. In a floor sweeping apparatus having a frame. mounting means within said frame for journably supporting floor treating means for axial rotation therewithin, wall means including a forward wall, a rear wall, and opposed side walls coupled to said frame means forming an enclosure about said floor treating means, said wall means having a debris receiving port formed therein, power means for imparting axial rotation to said floor treating means; a debris receiving chamber, conduit means coupled to said debris receiving port and providing fluid communication between said floor treating means enclosure and said debris receiving chamber, and fluid impeller means for providing gaseous fluid flow from said floor treating means enclosure to said debris receiving chamber;

a. skirt means coupled to said wall means and extending generally between at least one pair of opposed walls for isolating a portion of said enclosure from the ambience, said skirt means including a plurality of spaced apart generally parallelly disposed flexible sealing elements each having a lower free edge surface and being cooperatively arranged to define at least one enclosed seal chamber therebetween, and at least one vent opening formed in the innermost one of said sealing elements to provide gaseous fluid communication between said floor treating means enclosure and said seal chamber.

2. The floor sweeping apparatus as defined in claim 1 being particularly characterized in that said skirt means extend between opposed side lateral walls.

3. The floor sweeping apparatus as defined in claim 1 being particularly characterized in that first and second sealing elements are cooperatively arranged to form a seal pair.

4. The floor sweeping apparatus as defined in claim 3 being particularly characterized in that said seal pair is disposed at the rear wall of said floor treating means enclosure.

5. The floor sweeping apparatus as defined in claim 1 being particularly characterized in that a plurality of spaced apart vent openings are formed in said sealing element at a location spaced upwardly from the lower free edgesurface of said sealing element.

6. The floor sweeping apparatus as defined in claim 1 being particularly characterized in that the area of said vent opening is approximately equal to the area of said debris receiving port.

7. The floor sweeping apparatus as defined in claim 1 being particularly characterized in that said floor treating means is a cylindrical brush.

8. The floor sweeping apparatus as defined in claim 7 being particularly characterized in that said spaced apart sealing elements include first and second tandemly arranged sealing elements forming a seal pair.

9. The floor sweeping apparatus as defined in claim means enclosure.

It =0 i l 

1. In a floor sweeping apparatus having a frame, mounting means within said frame for journably supporting floor treating means for axial rotation therewithin, wall means including a forward wall, a rear wall, and opposed side walls coupled to said frame means forming an enclosure about said floor treating means, said wall means having a debris receiving port formed therein, power means for imparting axial rotation to said floor treating means; a debris receiving chamber, cOnduit means coupled to said debris receiving port and providing fluid communication between said floor treating means enclosure and said debris receiving chamber, and fluid impeller means for providing gaseous fluid flow from said floor treating means enclosure to said debris receiving chamber; a. skirt means coupled to said wall means and extending generally between at least one pair of opposed walls for isolating a portion of said enclosure from the ambience, said skirt means including a plurality of spaced apart generally parallelly disposed flexible sealing elements each having a lower free edge surface and being cooperatively arranged to define at least one enclosed seal chamber therebetween, and at least one vent opening formed in the innermost one of said sealing elements to provide gaseous fluid communication between said floor treating means enclosure and said seal chamber.
 2. The floor sweeping apparatus as defined in claim 1 being particularly characterized in that said skirt means extend between opposed side lateral walls.
 3. The floor sweeping apparatus as defined in claim 1 being particularly characterized in that first and second sealing elements are cooperatively arranged to form a seal pair.
 4. The floor sweeping apparatus as defined in claim 3 being particularly characterized in that said seal pair is disposed at the rear wall of said floor treating means enclosure.
 5. The floor sweeping apparatus as defined in claim 1 being particularly characterized in that a plurality of spaced apart vent openings are formed in said sealing element at a location spaced upwardly from the lower free edge surface of said sealing element.
 6. The floor sweeping apparatus as defined in claim 1 being particularly characterized in that the area of said vent opening is approximately equal to the area of said debris receiving port.
 7. The floor sweeping apparatus as defined in claim 1 being particularly characterized in that said floor treating means is a cylindrical brush.
 8. The floor sweeping apparatus as defined in claim 7 being particularly characterized in that said spaced apart sealing elements include first and second tandemly arranged sealing elements forming a seal pair.
 9. The floor sweeping apparatus as defined in claim 8 being particularly characterized in that said skirt means is disposed along said rear wall.
 10. The floor sweeping apparatus as defined in claim 1 being particularly characterized in that means are provided for adjustably supporting the elevation of said cylindrical brush.
 11. The floor sweeping apparatus as defined in claim 1 being particularly characterized in that said debris receiving chamber is provided with filter means for separating solids from air and for trapping debris moving to said debris receiving chamber from said floor treating means enclosure. 